JPS60244262A - Method of improving fish quality of cultured fish - Google Patents

Abstract

PURPOSE:To aim improvement of fish quality of culture fishes, by feeding glutathione to cultured fishes. CONSTITUTION:The amount of glutathione in feed blend is optional, but amount of glutathione in feeding is 5-80mg per kg weight of cultured fish daily. A feed comprising fish meal or minced fish as a main component may be cited as the feed, and, red sea bream, yellow tail, banded shrimp, etc. may be cited as the cultured fishes.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention provides for the administration of glutathione to cultured fish.
This invention relates to improving the meat quality of cultured fish and to a meat quality improving agent for cultured fish containing glutathione.

Conventional techniques It is known that vitamins can be used to improve the meat quality of farmed fish and to prevent diseases (August issue of Aquaculture).

98-103. '83).

Problems to be Solved by the Invention Normally, farmed fish such as sea bream and yellowtail are fed frozen fish such as frozen sardines and frozen kounago.

If these feeds are fresh, healthy farmed fish can be produced, but in general, feeds are not necessarily fresh, but are often slightly less fresh. Also, even if the food is fresh, if more than an hour has passed after thawing, the freshness will drop rapidly.

Farmed fish fed this kind of food are more susceptible to diseases.
It is vulnerable to changes in water temperature and is prone to death points, and when taken from the water to be shipped to the market, the freshness and preservation time of the flesh is shorter than that of wild fish, and the flesh tends to become soft. Excellent meat quality improving and disease preventing agents are being developed to solve these problems.

Means to Solve the Problem By administering glutathione to farmed fish, the quality of their flesh will be improved, death from diseases will be reduced, and life extension effects will appear.

When administering glutathione to cultured fish, it is usually advisable to mix glutathione with feed, but in order to mix glutathione well with feed, glutathione can be administered in a formulation, such as a formulation consisting of glutathione and an excipient. It is better to use it as Examples of excipients include lactose and glucose.

The amount of glutathione added in the feed is arbitrary, but the amount of glutathione when administered is 1 kg of body weight of cultured fish.
5 to 80 mg per day.

The feed may be one whose main ingredients are fish meal or minced fish meat, to which vitamins, minerals, etc. may be added as necessary.

Examples of fish for fish meal and minced fish include sardines, saury, sand eel, atka mackerel, mysids, shrimp, squid, and shellfish.

Applicable farmed fish include red sea bream, yellowtail, and prawn.

Examples are shown below.

Example 1 20 parts of glutathione and 980 parts of lactose are uniformly mixed to form a powder.

Example 2 2,000 yellowtail fish (approximately 3 kg/fish) were divided into two groups of 1,000 fish each, and the test group was treated with glutathione powder (Example 1) at a concentration of 20 mg/day/kg of fish body weight in sardine mince. The bait added with the food obtained from (the same applies hereafter),
The control group was given sardine mince for 13 consecutive days.

Before the first administration of exasperation (first day) and 10 days after the final administration (23rd day from the first day), five yellowtail were taken from each group.
The enzyme activity GOT (glutamic ox) in the blood
aloacetic transaminase) and GPT (glutamic pyruvic
transaminase). The results are shown in Table 1.

Table 1 (Unit: Carmen Unit) As is clear from Table 1, the GOT and GPT of the fish in the test group that ingested glutathione were significantly reduced.

In addition, on the 23rd day, five yellowtails were taken from each group and saran was made and sampled. The results are as follows.

The Saran in the test group that had just been cut was hard and had almost no oil floating on the soy sauce. Furthermore, the color of the meat was leaner than that of the control group. There was no discoloration of the flesh even after 8 hours, and it was chewy when put in the mouth. A slight discoloration was observed at 244 hours, but the firmness was not much different from that at 8 hours.

On the other hand, the saran in the control group that had just been cut was firm, but the quality of the oil was poor, with a lot of oil floating on top of the soy sauce. After 8 hours of cooking, the meat was slightly discolored and slightly chewy when put in the mouth. After 24 hours, the color had changed considerably and the texture had almost disappeared.

In addition, Saran for both groups was wrapped in Saran wrap and stored at 4°C.

Example 3 Using two fish cages in which 42,000 maggs (approximately 800 g/fish) were stocked, the test group received minced sardines with glutathione powder added (glutathione equivalent: 20 mg/day/kg), and the control group 1 minced sardine for each
It was given for 0 days. Five red sea bream were taken from each group before the first administration (first day) and 10 days after the final administration (20th day from the first day) at each facility, and GOT and GPT in their blood were measured. The results are shown in Table 2.

Table 2■ Also, on the 20th day, 45 radish from each group were made into saran and tasted.

Saran was sampled by 10 people, and all of them judged that the flesh of the red sea bream in the test group was chewier and had a slightly sweeter taste.

Example 4 300 Japanese yellowtail fish (approximately 80 g/fish) were divided into two groups (test group and control group) of 150 fish each, and for 15 days both groups were fed minced sardines that had been exposed to the sun for 3 hours after thawing. During this period, almost no growth was observed in the yellowtail, and 65 fish died in one group and 67 fish died in the other group.

After that, the test group received a mixture of sardine mince and glutathione powder (glutathione equivalent: 20 mg/day/kg).
Sardine mince was administered to the control group.

The animals were kept for 20 days after the start of administration, and the sudden occurrence of death in both groups was investigated. The results are shown in Table 3.

Table 3 (Number of alive fish) In the test group, 54 fish were still alive on the 20th day after the feed change, but in the control group, no fish were still alive on the 10th day.

Example 5゜90 prawns (approximately 10 g/fish), 30 shrimp each for 2 m
The test groups I and ■ were fed with Evian Kyowa (manufactured by Kyowa Hakko Co., Ltd.) to which glutathione powder was added at a concentration of 10 mg/day/kg and 20 mg Z day/kg in terms of glutathione. The control group was given Evian Kyowa for 30 days.

After that, each group of prawns was taken out of the water, stored overnight in a room at 5℃ in sawdust, and taken out on the morning of the 8th.
The prawns were returned to water, the dead prawns were removed, and the prawns were packed in sawdust again and stored in a room at 5°C.

This was repeated and the number of days until all the animals died was measured.

The results are shown in Table 4.

In Table 4, all of the test group ■ died on the 6th day, and the test group ■ died on the 7th day, but all of the control group died on the 4th day.

Effects of the Invention By administering glutathione to farmed fish, the meat quality of the farmed fish is improved and their lifespan is extended.

Claims (2)

[Claims] (1) A method for improving the meat quality of farmed fish by administering glutathione to them. (2) A meat quality improving agent for cultured fish containing glutathione.